forked from ajkeeton/fragroute
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathpkt.c
280 lines (234 loc) · 5.37 KB
/
pkt.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/*
* pkt.c
*
* Copyright (c) 2001 Dug Song <[email protected]>
*
* $Id: pkt.c,v 1.10 2002/04/07 22:55:20 dugsong Exp $
*/
#include "config.h"
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bget.h"
#include "pkt.h"
void
pkt_init(int size)
{
bectl(NULL, malloc, free, sizeof(struct pkt) * size);
}
struct pkt *
pkt_new(void)
{
struct pkt *pkt;
if ((pkt = bget(sizeof(*pkt))) == NULL)
return (NULL);
timerclear(&pkt->pkt_ts);
memset(&pkt->pkt_ev, 0, sizeof(pkt->pkt_ev));
pkt->pkt_data = pkt->pkt_buf + PKT_BUF_ALIGN;
pkt->pkt_eth = (struct eth_hdr *)pkt->pkt_data;
pkt->pkt_eth_data = pkt->pkt_data + ETH_HDR_LEN;
pkt->pkt_ip_data = pkt->pkt_data + ETH_HDR_LEN + IP_HDR_LEN;
pkt->pkt_tcp_data = NULL;
pkt->pkt_end = pkt->pkt_ip_data;
return (pkt);
}
struct pkt *
pkt_dup(struct pkt *pkt)
{
struct pkt *new;
off_t off;
if ((new = bget(sizeof(*new))) == NULL)
return (NULL);
off = new->pkt_buf - pkt->pkt_buf;
new->pkt_ts = pkt->pkt_ts;
memset(&new->pkt_ev, 0, sizeof(new->pkt_ev));
new->pkt_data = pkt->pkt_data + off;
new->pkt_eth = (pkt->pkt_eth != NULL) ?
(struct eth_hdr *)new->pkt_data : NULL;
new->pkt_eth_data = (pkt->pkt_eth_data != NULL) ?
pkt->pkt_eth_data + off : NULL;
new->pkt_ip_data = (pkt->pkt_ip_data != NULL) ?
pkt->pkt_ip_data + off : NULL;
new->pkt_tcp_data = (pkt->pkt_tcp_data != NULL) ?
pkt->pkt_tcp_data + off : NULL;
memcpy(new->pkt_data, pkt->pkt_data, pkt->pkt_end - pkt->pkt_data);
new->pkt_end = pkt->pkt_end + off;
return (new);
}
void
pkt_decorate(struct pkt *pkt)
{
u_char *p;
int hl, len, off;
pkt->pkt_data = pkt->pkt_buf + PKT_BUF_ALIGN;
pkt->pkt_eth = NULL;
pkt->pkt_ip = NULL;
pkt->pkt_ip_data = NULL;
pkt->pkt_tcp_data = NULL;
p = pkt->pkt_data;
if (p + ETH_HDR_LEN > pkt->pkt_end)
return;
pkt->pkt_eth = (struct eth_hdr *)p;
p += ETH_HDR_LEN;
if (p + IP_HDR_LEN > pkt->pkt_end)
return;
pkt->pkt_eth_data = p;
/* If IP header length is longer than packet length, stop. */
hl = pkt->pkt_ip->ip_hl << 2;
if (p + hl > pkt->pkt_end) {
pkt->pkt_ip = NULL;
return;
}
/* If IP length is longer than packet length, stop. */
len = ntohs(pkt->pkt_ip->ip_len);
if (p + len > pkt->pkt_end)
return;
/* If IP fragment, stop. */
off = ntohs(pkt->pkt_ip->ip_off);
if ((off & IP_OFFMASK) != 0 || (off & IP_MF) != 0)
return;
pkt->pkt_end = p + len;
p += hl;
/* If transport layer header is longer than packet length, stop. */
switch (pkt->pkt_ip->ip_p) {
case IP_PROTO_ICMP:
hl = ICMP_HDR_LEN;
break;
case IP_PROTO_TCP:
if (p + TCP_HDR_LEN > pkt->pkt_end)
return;
hl = ((struct tcp_hdr *)p)->th_off << 2;
break;
case IP_PROTO_UDP:
hl = UDP_HDR_LEN;
break;
default:
return;
}
if (p + hl > pkt->pkt_end)
return;
pkt->pkt_ip_data = p;
p += hl;
/* Check for transport layer data. */
switch (pkt->pkt_ip->ip_p) {
case IP_PROTO_ICMP:
pkt->pkt_icmp_msg = (union icmp_msg *)p;
switch (pkt->pkt_icmp->icmp_type) {
case ICMP_ECHO:
case ICMP_ECHOREPLY:
hl = sizeof(pkt->pkt_icmp_msg->echo);
break;
case ICMP_UNREACH:
if (pkt->pkt_icmp->icmp_code == ICMP_UNREACH_NEEDFRAG)
hl = sizeof(pkt->pkt_icmp_msg->needfrag);
else
hl = sizeof(pkt->pkt_icmp_msg->unreach);
break;
case ICMP_SRCQUENCH:
case ICMP_REDIRECT:
case ICMP_TIMEXCEED:
case ICMP_PARAMPROB:
hl = sizeof(pkt->pkt_icmp_msg->srcquench);
break;
case ICMP_RTRADVERT:
hl = sizeof(pkt->pkt_icmp_msg->rtradvert);
break;
case ICMP_RTRSOLICIT:
hl = sizeof(pkt->pkt_icmp_msg->rtrsolicit);
break;
case ICMP_TSTAMP:
case ICMP_TSTAMPREPLY:
hl = sizeof(pkt->pkt_icmp_msg->tstamp);
break;
case ICMP_INFO:
case ICMP_INFOREPLY:
case ICMP_DNS:
hl = sizeof(pkt->pkt_icmp_msg->info);
break;
case ICMP_MASK:
case ICMP_MASKREPLY:
hl = sizeof(pkt->pkt_icmp_msg->mask);
break;
case ICMP_DNSREPLY:
hl = sizeof(pkt->pkt_icmp_msg->dnsreply);
break;
default:
hl = pkt->pkt_end - p + 1;
break;
}
if (p + hl > pkt->pkt_end)
pkt->pkt_icmp_msg = NULL;
break;
case IP_PROTO_TCP:
if (p < pkt->pkt_end)
pkt->pkt_tcp_data = p;
break;
case IP_PROTO_UDP:
if (pkt->pkt_ip_data + ntohs(pkt->pkt_udp->uh_ulen) <=
pkt->pkt_end)
pkt->pkt_udp_data = p;
break;
}
}
void
pkt_free(struct pkt *pkt)
{
brel(pkt);
}
void
pktq_reverse(struct pktq *pktq)
{
struct pktq tmpq;
struct pkt *pkt, *next;
TAILQ_INIT(&tmpq);
for (pkt = TAILQ_FIRST(pktq); pkt != TAILQ_END(pktq); pkt = next) {
next = TAILQ_NEXT(pkt, pkt_next);
TAILQ_INSERT_HEAD(&tmpq, pkt, pkt_next);
}
*pktq = tmpq;
}
void
pktq_shuffle(rand_t *r, struct pktq *pktq)
{
static struct pkt **pvbase;
static int pvlen;
struct pkt *pkt;
int i;
i = 0;
TAILQ_FOREACH(pkt, pktq, pkt_next) {
i++;
}
if (i > pvlen) {
pvlen = i;
if (pvbase == NULL)
pvbase = malloc(sizeof(pkt) * pvlen);
else
pvbase = realloc(pvbase, sizeof(pkt) * pvlen);
}
i = 0;
TAILQ_FOREACH(pkt, pktq, pkt_next) {
pvbase[i++] = pkt;
}
TAILQ_INIT(pktq);
rand_shuffle(r, pvbase, i, sizeof(pkt));
while (--i >= 0) {
TAILQ_INSERT_TAIL(pktq, pvbase[i], pkt_next);
}
}
struct pkt *
pktq_random(rand_t *r, struct pktq *pktq)
{
struct pkt *pkt;
int i;
i = 0;
TAILQ_FOREACH(pkt, pktq, pkt_next) {
i++;
}
i = rand_uint32(r) % (i - 1);
pkt = TAILQ_FIRST(pktq);
while (--i >= 0) {
pkt = TAILQ_NEXT(pkt, pkt_next);
}
return (pkt);
}